Atrial Septal Defects (ASDs) is usually due to the incomplete closure of what?
the oval foramen
Large ASDs are severe because they allow what to occur?
allow oxygenated blood from the lungs to be shunted from the left atrium through the ASD into the right atrium leaving to RA enlargement and dilation of the pulmonary trunk.
Left to right shunt of blood overloads the pulmonary vasular system resulting in hypertrophy of the right atrium and ventricle and pulmonary arteries.
Severe ASDs cause what to occur?
Left to right shunt of blood which overloads the pulmonary vasular system resulting in hypertrophy of the right atrium and ventricle and pulmonary arteries.
What is the most serious ASD?
Cor triloculare biventriculare
-complete absence of the atrial septum
What is the most common cardiac defect?
VSDs (Ventricular Septal Defects)
Accounts for 25% of all congenital heart defects.
What is the most common place for VSDs to occur?
the membranous part of the IVS, which develops from the muscular part and has complex embryological origin
VSDs cause what to occur?
a left to right shunt of blood through the defect
leads to severe pulmonary disease (hypertension, increased BP)
VSDs can also cause muscular part of the VS to close prematurely
ASDs can be cause by what two (2) things?
1.) Excessive resorption of the septum primum
2.) Absence of the septum secundum
Look @ picture, located the two structures
What is tricuspid atresia?
obliteration of the right atrioventricular orifice
missing tricuspid valve, so no right A/V connection
shows a patent oval foramen
underdeveloped right ventricle
left ventricle hypertrophy
Blood is mixed in the left atrium
Three types of VSDs?
1.) Defect of membranous part of IVS
2.) Defect of muscular part of IVS
3.) Absences of IVS (single or common ventricle)
What arteries supply the myocardium and epicardium?
The ____________ arises from the right aortic sinus of the ascending aorta and passes to the right side of the pulmonary trunk, running in the coronary sulcus.
Right Coronary Artery (RCA)
What branch does the RCA give off near its origin? what does this branch supply?
sinuatrial nodal branch
supplies the SA NODE
The RCA descends in the coronary sulcus and gives off the _______________, which supplies the right border of the heart.
right marginal branch
At the posterior aspect of the heart, the crux the junction of the interatrial and interventricular IV septa between the four chambers, the RCA gives rise to _________________.
What does this branch supply?
atrioventricular nodal branch--> supplies the AV NODE.
AV node is supplied by what branch?
atrioventricular nodal branch off the RCA (AV node is part of the conduction system of the heart)
The SA node is supplied by what branch?
sinuatrial nodal branch of the RCA (SA node is part of the conduction system of the heart)
The RCA supplies what regions of the heart?
SA node (60% of people)
AV node (80% of people)
Part of LV (diaphragmatic surface)
Posterior 1/3 of IV septum
The ______________ arises from the left aortic sinus of the ascending aorta, passes btween the left auricle and left side of the pulmonary trunk and runs in the coronary sulcus
left coronary artery (LCA)
In 40% of people the SA nodal branch arises from the circumflex branch of the _______
What are the branches of the LCA?
anterior IV branch, which passes along the IV groove to the apex of the heart (in many people the anterior IV branch gives rise to a lateral branch or diagonal artery)
circumflex branch of the LCA (left marginal branch of circumflex branch follows the left margin of the heart and supplies the left ventricle
What does the LCA supply?
most of LV
Part of RV
Most of the IVS, and the AV bundle
SA node (in 40% of people)
Dominance of the RCA occurs in what % of the population?
Dominance of the LCA occurs in what % of the population?
What are two variations of the coronary arteries?
missing coronary artery
left side of heart is supplied by right coronary artery
What is the main vein of the heart?
The heart is drained mainly by veins that empty into the _________and by small veins that empty into the right atrium.
Where is the coronary sinus located?
posterior surface of the heart in the coronary groove.
The coronary sinus recieves ____________at its left end and the middle cardiac vein and small cardiac vein at its right end.
great cardiac vein!
What is the main tributary of the coronary sinus?
The great cardiac vein.
The great cardiac vein drains the areas of the heart supplied by what artery?
Lymphatic drainage of the heart is unique why?
it has "crossed" drainage,
lymph from the left A/V drains to the right venous junction
lymph from the right A/V drains to the left venous junction.
What is the conduction system of the heart pathway?
Conduction block causes ?
bradycardia (low hr)
Conduction block can cause tachycardia how?
What is the bundle of Kent (Bypass Tract)?
Some people have connections between their atria and ventricles, connected by a tract of myocardium called the bundle of kent
This allows conduction through the myocardium
Know where the heart sits in relation to the layers associated with the pericardium.
Inflammation of the pericardium (pericarditis) usually causes chest pain, it can also make the serous pericardium rough, what is detectable if this is occuring in a patient?
If there is pericarditis, friction of the roughened surfaces may sound like the rustle of silk when listening over the left sternal border and upper ribs.******
This is called a Pericardial Friction Rub
Some inflammatory diseases produce __________ (passage of fluid from the pericardial capillaries into the pericardial cavity or an accumulation of pus) as a result the heart can become compressed.
What often occurs along with congestive heart failure that involves the pericardium?
Non-inflammatory pericardial effusions
Due to venous blood returning to the heart at a rate that exceeds cardiac output, producing right cardiac hypertension (elevated BP in Right side of heart)
What is significant clinically regarding the Transverse Pericardial Sinus?
Important to Cardiac Surgeons
Allows a clamp or ligature to be placed around the ascending aorta or pulmonary trunk, hooked up to a coronary bypass machine and then tightening the ligature to stop or divert circulation in these arteries while performing cardiac surgery, like coronary artery bypass grafting
Why is Cardiac Tamponade so dangerous?
If extensive pericardial effusion exists, the comprimised volume of the sac does not allow FULL expansion of the heart, limiting the amount of blood the heart can recieve, reducing CO.
What is hemopericardium?
blood in the pericardial cavity, caused by weakened area of heart muscle, possibly due to a previous MI or previous surgery.
produces cardiac tamponade (lots of pericardial effusion)
What is pneumopericardium?
When patients with pneumothorax--air or gas in the pleural cavity dissects along the CT plans and enters the pericardial sac.